Irritable bowel syndrome-specific volatile organic compounds in faecal headspace do not associate with classical...

Area of Science:

• Gastroenterology and Metabolism
• Microbiome Research
• Biomarker Discovery

Background:

• Irritable Bowel Syndrome (IBS) is a gut-brain interaction disorder diagnosed via symptom-based Rome criteria, which categorize patients into subtypes based on stool patterns.
• The biological basis for these current IBS subtypes remains unclear, necessitating novel approaches to understand disease heterogeneity.
• Faecal volatile organic compounds (VOCs) offer a window into gut microbial and host intestinal processes, potentially revealing pathophysiological differences in IBS.

Purpose of the Study:

• To investigate whether faecal VOC profiles can differentiate IBS patients from healthy controls.
• To explore the association between faecal VOC profiles and existing Rome III-based IBS subtypes.
• To assess the potential of VOC analysis as a non-invasive tool for IBS characterization.

Main Methods:

• Faecal headspace VOCs were profiled in 164 IBS patients and 143 healthy controls using gas chromatography-mass spectrometry.
• Random forest models were used for data imputation and to identify discriminatory VOCs.
• Partial least squares regression corrected for faecal water content, and regularized MANOVA evaluated associations with Rome III subtypes.

Main Results:

• A total of 39 VOCs were significantly altered in IBS patients compared to controls.
• A classification model achieved an area under the curve of 0.82, demonstrating robust separation between IBS patients and healthy individuals.
• No significant association was found between faecal VOC profiles and the Rome III-based IBS subtypes.

Conclusions:

• Faecal VOC profiling is a promising non-invasive method for studying IBS and distinguishing patients from healthy individuals.
• Current stool-based IBS subtyping lacks a clear metabolic basis, as indicated by the lack of association with VOC profiles.
• Future research should integrate VOC analysis with other omics data to develop biologically relevant IBS classifications for personalized therapies.